Answer:
![(b)/(50)](https://img.qammunity.org/2019/formulas/mathematics/college/e09y7uj4j84xzzp52smswi60n5yd219di4.png)
Explanation:
Given: The total number of students donated books in Hannah's school = 150
The number of books donated by students = b
The average number of books each student donated=
![\frac{\text{total books donated}}{\text{total students}}](https://img.qammunity.org/2019/formulas/mathematics/college/xv074a8kixh97grnzl01szf62qso7h0vm4.png)
Thus, The average number of books each student donated=
![(b)/(150)](https://img.qammunity.org/2019/formulas/mathematics/college/1tg9i0hrecl7uotdjoy50deoinsw8sv1a6.png)
Since, Hannah donated 3 times as many as the average number of books each student donated.
Then , the number of books donated by Hannah=
![3*(b)/(150)=(b)/(50)](https://img.qammunity.org/2019/formulas/mathematics/college/crumfult6lt0odywpbc3798adjgvr065ov.png)